Methods for inhibiting the binding of endosialin to ligands

Abstract

The invention provides methods for inhibiting the interaction of endosialin with endosialin ligands. The inhibition is effectuated on the genetic level, by inhibiting endosialin gene expression, and on the protein level, by blocking the interaction of cell-surface expressed endosialin with ligands such as fibronectin and collagen. The invention provides methods for identifying inhibitors of the interaction of endosialin with endosialin ligands. Also provided are methods for inhibiting angiogenesis and neovascularization in vivo and in vitro.

1. A method for identifying agonists or antagonists of the interaction of endosialin with a ligand for endosialin, said ligand for endosialin comprising collagen I, collagen IV, fibronectin, the 70 kDa N-terminal fragment of fibronectin, the 45 kDa gelatin binding fragment of fibronectin, or the 30 kDa heparin binding fragment of fibronectin, said method comprising contacting endosialin with said ligand for endosialin in the presence and absence of a test compound and quantifiably measuring the interaction of endosialin with the ligand, wherein an increase or a decrease in the level of interaction of endosialin with said ligand in the presence of the test compound indicates that the test compound is an agonist or antagonist, respectively, of the interaction of endosialin with said ligand. 
     
     
       2. The method of  claim 1 , wherein the endosialin is bound to a cell membrane, a cell membrane fragment, or an artificial lipid bilayer. 
     
     
       3. The method of  claim 2 , wherein the wherein the cell membrane or cell membrane fragment is from a mammalian cell. 
     
     
       4. The method of  claim 3 , wherein the mammalian cell is a stable cell or stable cell line expressing endosialin. 
     
     
       5. The method of  claim 1 , wherein the ligand is collagen I, collagen IV or fibronectin. 
     
     
       6. The method of  claim 1 , wherein the endosialin is bound to a solid support. 
     
     
       7. The method of  claim 1 , wherein the ligand is bound to a solid support. 
     
     
       8. A method for identifying an agonist or antagonist that modulates cell adhesion comprising
 (a) contacting a mammalian cell expressing endosialin with a ligand for endosialin in the presence and absence of a test compound, said ligand for endosialin comprising collagen I, collagen IV, fibronectin, the 70 kDa N-terminal fragment of fibronectin, the 45 kDa gelatin binding fragment of fibronectin, or the 30 kDa heparin binding fragment of fibronectin; and 
 (b) quantifiably measuring cell adhesion, 
 wherein an increase or decrease in the level of adhesion in the presence of the test compound indicates that the test compound is an agonist or antagonist, respectively, of cell adhesion.